1. Field of the Invention
The present invention relates to a M-ary phase shift keying (hereinafter referred to as M-PSK), and more particularly, to an apparatus and method of improving degradation of a symbol error rate caused by a phase error and estimation of a phase error when an M-PSK signal is demodulated.
2. Description of the Related Art
Generally, an M-PSK system is broken down into a quadrature phase shift keying system, an 8-PKSK system and a 16-PSK system with respect to a modulation level M value. In most of wireless communication systems, the QPSK is used, but in a recently announced enhanced data for global evolution (EDGE) standard specification, the 8-PSK is employed in order to achieve a high transmission speed. Meanwhile, all M-PSK systems have phase errors occurring in a phase-locked loop and the bigger the phase error is, the higher the symbol error probability of the M-PSK system becomes.